Apparatus, methods, computer programs, and non-transitory computer readable storage mediums for controlling a power generation system

ABSTRACT

Apparatus for controlling a power generation system, the apparatus comprising a controller configured to: identify a trigger indicative of a future change in electrical power output by the power generation system to a first power level; control the power generation system to change electrical power output to a second power level in response to the trigger, the second power level being equal to, or different to the first power level; and control supply of at least a portion of the electrical power output from the power generation system at the second power level to an electrical energy storage system to charge the electrical energy storage system

CROSS-REFERENCE TO RELATED APPLICATIONS

This specification is based upon and claims the benefit of priority fromUK Patent Application Number 1710404.3 filed on 29 Jun. 2017, the entirecontents of which are incorporated herein by reference.

BACKGROUND Technical Field

The present disclosure concerns apparatus, methods, computer programs,and non-transitory computer readable storage mediums for controlling apower generation system.

Description of the Related Art

Power generation systems may take a relatively long period of time toreach maximum power output. For example, a gas turbine engine may takeapproximately ten seconds to increase power output from an idle poweroutput to a maximum (or high) power output. Gas turbine engine transientperformance, including acceleration response, is typically limited bythe amount of ‘overfueling’ that the gas turbine engine can toleratewithout exceeding allowable compressor surge margins. At low enginespeeds (and thus low power outputs) the allowable overfueling is smalland the gas turbine acceleration response is relatively slow. As theshaft speed of the gas turbine engine increases, the allowableoverfueling increases rapidly and the gas turbine acceleration responseis relatively fast (that is, the gas turbine engine can accelerate muchmore rapidly). This may pose a challenging requirement on accelerationcontrol schedules in order for gas turbine engines to start from lowpower and provide large amounts of thrust and power in short timescales. Similar constraints also apply to deceleration schedules.

SUMMARY

According to a first aspect there is provided apparatus for controllinga power generation system, the apparatus comprising a controllerconfigured to: identify a trigger indicative of a future change inelectrical power output by the power generation system to a first powerlevel; control the power generation system to change electrical poweroutput to a second power level in response to the trigger, the secondpower level being equal to, or different to, the first power level; andcontrol supply of at least a portion of the electrical power output fromthe power generation system at the second power level to an electricalenergy storage system to charge the electrical energy storage system.

The trigger may be indicative of a future increase in electrical poweroutput by the power generation system. The second power level may beequal to, or less than, the first power level.

The trigger may be indicative of a future decrease in electrical poweroutput by the power generation system. The second power level may beequal to, or greater than the first power level.

The controller may be configured to: control the power generation systemto change electrical power output to the first power level from thesecond power level.

The controller may be configured to: control supply of electrical poweroutput from the power generation system to one or more motors of apropulsion system.

The controller may be configured to: control supply of electrical poweroutput from the electrical energy storage system to one or more motorsof a propulsion system.

The controller may be configured to: receive a trigger signal from auser input device; and wherein the controller is configured to identifythe trigger using the received trigger signal.

The controller may be configured to: receive location data from a globalpositioning sensor; and wherein the controller is configured to identifythe trigger using the location data from the global positioning sensor.

A vehicle may comprise the power generation system. The controller maybe configured to identify the trigger using an operating mode of acomponent of the vehicle.

The power generation system may comprise a gas turbine engine.

The electrical energy storage system may include one or more batteriesand/or one or more supercapacitors.

According to a second aspect there is provided a vehicle comprisingapparatus as described in any of the preceding paragraphs.

According to a third aspect there is provided a power station comprisingapparatus as described in any of the preceding paragraphs.

According to a fourth aspect there is provided a method of controlling apower generation system, the method comprising: identifying a triggerindicative of a future change in electrical power output by the powergeneration system to a first power level; controlling the powergeneration system to change electrical power output to a second powerlevel in response to the trigger, the second power level being equal to,or different to the first power level; and controlling supply of atleast a portion of the electrical power output from the power generationsystem at the second power level to an electrical energy storage systemto charge the electrical energy storage system.

The trigger may be indicative of a future increase in electrical poweroutput by the power generation system. The second power level may beequal to, or less than, the first power level.

The trigger may be indicative of a future decrease in electrical poweroutput by the power generation system. The second power level may beequal to, or greater than the first power level.

The method may further comprise controlling the power generation systemto change electrical power output to the first power level from thesecond power level.

The method may further comprise controlling supply of electrical poweroutput from the power generation system to one or more motors of apropulsion system.

The method may further comprise controlling supply of electrical poweroutput from the electrical energy storage system to one or more motorsof a propulsion system.

The method may further comprise receiving a trigger signal from a userinput device. The trigger may be identified using the received triggersignal.

The method may further comprise receiving location data from a globalpositioning sensor. The trigger may be identified using the locationdata from the global positioning sensor.

A vehicle may comprise the power generation system. The trigger may beidentified using an operating mode of a component of the vehicle.

The power generation system may comprise a gas turbine engine.

The electrical energy storage system may include one or more batteriesand/or one or more supercapacitors.

According to a fifth aspect there is provided a computer program that,when read by a computer, causes performance of the method as describedin any of the preceding paragraphs.

According to a sixth aspect there is provided a non-transitory computerreadable storage medium comprising computer readable instructions that,when read by a computer, cause performance of the method as described inany of the preceding paragraphs.

According to a seventh aspect there is provided a signal comprisingcomputer readable instructions that, when read by a computer, causeperformance of the method as described in any of the precedingparagraphs.

The skilled person will appreciate that except where mutually exclusive,a feature described in relation to any one of the above aspects may beapplied mutatis mutandis to any other aspect. Furthermore except wheremutually exclusive any feature described herein may be applied to anyaspect and/or combined with any other feature described herein.

DESCRIPTION OF THE DRAWINGS

Embodiments will now be described by way of example only, with referenceto the Figures, in which:

FIG. 1 illustrates a schematic diagram of a system comprising apparatusfor controlling a power generation system according to various examples;

FIG. 2 illustrates a flow diagram of a method of controlling a powergeneration system according to various examples;

FIG. 3 illustrates a graph of electrical power output of a powergeneration system versus time according to a first example;

FIG. 4 illustrates a graph of electrical power output of a powergeneration system versus time according to a second example;

FIG. 5 illustrates a graph of electrical power output of a powergeneration system versus time according to a third example;

FIG. 6 illustrates a schematic diagram of a vehicle comprising a systemaccording to various examples; and

FIG. 7 illustrates a schematic diagram of a power station comprising asystem according to various examples.

DETAILED DESCRIPTION

In the following description, the terms ‘connected’ and ‘coupled’ meanoperationally connected and coupled. It should be appreciated that theremay be any number of intervening components between the mentionedfeatures, including no intervening components.

FIG. 1 illustrates a schematic diagram of a system 10 comprisingapparatus 12, a power generation system 14, an electrical energy storagesystem 16, a propulsion system 18, and a component 20. In some examples,the system 10 may be a module. As used herein, the wording ‘module’refers to a device or apparatus where one or more features are includedat a later time and, possibly, by another manufacturer or by an enduser. For example, where the system 10 is a module, the system 10 mayonly include the apparatus 12, and the remaining features may be addedby another manufacturer, or by an end user. In another example where thesystem 10 is a module, the system 10 may only include the apparatus 12,the power generation system 14 and the propulsion system 18, and theremaining features (for example, the electrical energy storage system 16and the component 20) may be added by another manufacturer, or by an enduser.

The apparatus 12 is configured to control the power generation system 14and may include a controller 22, a user input device 24, and a globalpositioning sensor 26. In some examples, the apparatus 12 may be amodule and may only include the controller 22, and the remainingfeatures (such as the user input device 24 and the global positioningsensor 26) may be added by another manufacturer, or by an end user.

The controller 22 may comprise any suitable circuitry to causeperformance of the methods described herein and as illustrated in FIG.2. The controller 22 may comprise: control circuitry; and/or processorcircuitry; and/or at least one application specific integrated circuit(ASIC); and/or at least one field programmable gate array (FPGA); and/orsingle or multi-processor architectures; and/or sequential/parallelarchitectures; and/or at least one programmable logic controllers(PLCs); and/or at least one microprocessor; and/or at least onemicrocontroller; and/or a central processing unit (CPU); and/or agraphics processing unit (GPU), to perform the methods.

In various examples, the controller 22 may comprise at least oneprocessor 28 and at least one memory 30. The memory 30 stores a computerprogram 32 comprising computer readable instructions that, when read bythe processor 28, causes performance of the methods described herein,and as illustrated in FIG. 2. The computer program 32 may be software orfirmware, or may be a combination of software and firmware.

The processor 28 may include at least one microprocessor and maycomprise a single core processor, may comprise multiple processor cores(such as a dual core processor or a quad core processor), or maycomprise a plurality of processors (at least one of which may comprisemultiple processor cores).

The memory 30 may be any suitable non-transitory computer readablestorage medium, data storage device or devices, and may comprise a harddisk drive (HDD) and/or a solid state drive (SSD). The memory 30 may bepermanent non-removable memory, or may be removable memory (such as auniversal serial bus (USB) flash drive or a secure digital card). Thememory 30 may include: local memory employed during actual execution ofthe computer program; bulk storage; and cache memories which providetemporary storage of at least some computer readable or computer usableprogram code to reduce the number of times code may be retrieved frombulk storage during execution of the code.

The computer program 32 may be stored on a non-transitory computerreadable storage medium 34. The computer program 32 may be transferredfrom the non-transitory computer readable storage medium 34 to thememory 30. The non-transitory computer readable storage medium 34 maybe, for example, a USB flash drive, a secure digital (SD) card, anoptical disc (such as a compact disc (CD), a digital versatile disc(DVD) or a Blu-ray disc). In some examples, the computer program 32 maybe transferred to the memory 30 via a signal 36 (such as a wirelesssignal or a wired signal).

Input/output devices may be coupled to the controller 22 either directlyor through intervening input/output controllers. Various communicationadaptors may also be coupled to the controller 22 to enable theapparatus 12 to become coupled to other apparatus or remote printers orstorage devices through intervening private or public networks.Non-limiting examples include modems and network adaptors of suchcommunication adaptors.

The user input device 24 may comprise any suitable device for enablingan operator to provide a signal to the controller 22. For example, theuser input device 24 may comprise one or more of a keyboard, a keypad, atouchpad, a touchscreen display, a computer mouse, a joystick, a yoke, abutton, a switch, or a throttle. The controller 22 is configured toreceive signals from the user input device 24.

The global positioning sensor 26 may be any global navigation satellitesystem (GNSS) sensor and is configured to sense a location of the powergeneration system 14 and to generate location data. For example, theglobal positioning sensor 26 may comprise a global positioning system(GPS) sensor, and/or a Galileo sensor, and/or a Russian GlobalNavigation Satellite System (GLONASS) sensor, and/or a BeiDou NavigationSatellite System (BDS) sensor. The controller 22 is configured toreceive the location data from the global positioning sensor 26.

The power generation system 14 may comprise any suitable engines,system, or mechanism for generating electrical energy. For example, thepower generation system 14 may comprise one or more gas turbine engines38, and/or a reciprocating engine (such as a diesel engine), and/or anuclear reactor for generating electrical energy.

The controller 22 is configured to control the electrical power outputfrom the power generation system 14. For example, where the powergeneration system 14 comprises the one or more gas turbine engines 38,the controller 22 may be configured to control the supply of fuel to theone or more gas turbine engines 38 to increase and decrease the shaftspeed of the gas turbine engines 38, and thus the electrical poweroutput by the gas turbine engines 38.

The controller 22 is configured to control the power generation system14 to provide a part, or all of the electrical power output to theelectrical energy storage system 16. Additionally, the controller 22 isconfigured to control the power generation system 14 to provide a part,or all of the electrical power output to the propulsion system 18. Itshould be appreciated that the controller 22 may control the powergeneration system 14 to output electrical power to the electrical energystorage system 16 and the propulsion system 18 simultaneously.

The electrical energy storage system 16 may include any suitable deviceor devices for storing electrical energy generated by the powergeneration system 14. For example, the electrical energy storage system16 may include one or more batteries 40 and/or one or moresupercapacitors 42. The controller 22 is configured to control supply ofelectrical power output from the electrical energy storage system 16 tothe propulsion system 18.

The propulsion system 18 is configured to receive electrical energy fromthe power generation system 14 and/or the electrical energy storagesystem 16 and to use the electrical energy to generate thrust to propelthe system 10. For example, the propulsion system 18 may comprise one ormore electrical motors 44 and one or more fans 46. The one or moreelectrical motors 44 are configured to convert electrical power intomechanical power to rotate the one or more fans 46 and thus generatethrust.

The component 20 may be a component of a vehicle or a power station, ormay be an assembly of components of a vehicle or a power station. Asillustrated in FIG. 5, a vehicle 100 (such as an aircraft, a watercraft,or a land vehicle) may comprise the system 10. For example, where thevehicle is an aircraft, the component 20 may include a flap in a wing ofthe aircraft. By way of another example, where the vehicle is anaircraft, the component 20 may include a landing gear of the aircraft.As illustrated in FIG. 6, a power station 101 may comprise the system10, and the component 20 may include one or more valves of the powerstation 101. The component 20 may receive electrical power from theelectrical energy storage system 16 and/or from the power generationsystem 38. Arrows representing the supply of electrical power to thecomponent 20 are not illustrated to maintain the clarity of FIG. 1.

The operation of the system 10 is described in the following paragraphswith reference to FIGS. 2 to 5.

At a time T0, the power generation system 14 has an electrical poweroutput of P3. In the examples illustrated in FIGS. 3 & 4, the electricalpower output P3 is an idle power output of the one or more gas turbineengines 38 where the turbine shaft speed is three thousand revolutionsper minute. In the example illustrated in FIG. 5, the electrical poweroutput P3 is a relatively high (or maximum) power output of the one ormore gas turbine engines 38 where the turbine shaft speed is tenthousand revolutions per minute.

At block 48, the method may include receiving a signal at a time T1. Forexample, an operator may know that a transient manoeuvre (such asaircraft take off, landing, or taxiing) is to occur in the near futureand may operate the user input device 24 at the time T1 to provide atrigger signal to the controller 22. By way of another example, thecontroller 22 may receive location data in a signal from the globalpositioning sensor 26 at the time T1.

At block 50, the method includes identifying a trigger indicative of afuture change in electrical power output by the power generation system14 to a first power level P1. For example, where the controller 22 hasreceived a trigger signal from the user input device 24, the controller22 may identify the trigger using the received trigger signal. By way ofanother example, where the controller 22 has received location data in asignal from the global positioning sensor 26, the controller 22 mayidentify the trigger by determining whether the location of the globalpositioning sensor 26 is within a predetermined geographical area (forexample, a runway at an airport) and thus indicative that a transientmanoeuvre is to occur (aircraft take off for example). In a furtherexample where the system 10 includes the component 20, the controller 22may identify the trigger using an operating mode of the component 20.For example, the controller 22 may identify the trigger by determiningthat flaps on a wing of an aircraft are extended.

At block 52, the method includes controlling the power generation system14 to change electrical power output to a second power level P2 inresponse to the trigger. For example, the controller 22 may increase thesupply of fuel to the one or more gas turbine engines 38 in response tothe identification of the trigger in block 50. As illustrated in FIGS. 3and 4, the electrical power output from the power generation system 14increases at, or shortly after time T1, to the second power level P2which is reached at time T2. As illustrated in FIG. 5, the electricalpower output from the power generation system 14 decreases at, orshortly after time T1, to the second power level P2 which is reached attime T2.

At block 54, the method includes controlling supply of at least aportion of the electrical power output from the power generation system14 at the second power level P2 to the electrical energy storage system16 to charge the electrical energy storage system 16. For example, atany time between T1 and T2 in FIGS. 3, 4 and 5, the controller 22 maycontrol the supply of at least a portion of the electrical power outputfrom the power generation system 14 to the electrical energy storagesystem 16 to charge the electrical energy storage system 16.

At block 56, the method may include controlling the power generationsystem 14 to change electrical power output to the first power level P1from the second power level P2. As illustrated in FIG. 3, the electricalpower output from the power generation system 14 may be constant at thesecond power level P2 between times T2 and T3, and at time T3, thecontroller 22 controls the power generation system 14 to increaseelectrical power output to the first power level P1. At time T4, theelectrical power output from the power generation system 14 reaches thefirst power level P1. Alternatively, as illustrated in FIG. 4, thecontroller 22 may control the power generation system 14 to increaseelectrical power output to the first power level at time T2 (that is,the electrical power output from the power generation system 14 may notbe held constant at the second power level P2 for a period of time). Attime T3, the electrical power output from the power generation system 14reaches the first power level P1. As illustrated in FIG. 5, thecontroller 22 may control the power generation system 14 to decreaseelectrical power output to the first power level P1 at time T2.

At block 58, the method may include controlling supply of electricalpower output from the power generation system 14 to the one or moremotors 44 of the propulsion system 18. For example, at time T3 asillustrated in FIG. 3, or at time T2 as illustrated in FIG. 4, thecontroller 22 may control the power generation system 14 to supply onehundred percent of electrical power output to the one or more motors 44of the propulsion system 18. In another example, at time T3 asillustrated in FIG. 3, or at time T2 as illustrated in FIG. 4, thecontroller 22 may control the power generation system 14 to supply aportion of electrical power output to the one or more motors 44 of thepropulsion system 18. The portion of electrical power output supplied tothe propulsion system 18 may be equal to or greater than fifty percent,or may be equal to or greater than sixty percent, or may be equal to orgreater than seventy percent, or may be equal to or greater than eightypercent, or may be equal to or greater than ninety percent. Theremaining electrical power output may be supplied to other components(such as the electrical systems of an aircraft for example).

In the example illustrated in FIG. 5, at any time after T1 thecontroller 22 may control the power generation system 14 to supply aportion of the electrical power output to the one or more motors 44 ofthe propulsion system 18, and to supply a portion of the electricalpower output to the electrical energy storage system 16.

In some examples, the electrical power output from the power generationsystem 14 may be supplied to the electrical energy storage system 16until after the first electrical power output P1 has been reached. Forexample, in FIG. 3 the electrical power output from the power generationsystem 14 may be supplied to the electrical energy storage system 16 atany time from T1 and until any time after T4 (that is, after the firstelectrical power output P1 has been reached). By way of another example,in FIG. 4 the electrical power output from the power generation system14 may be supplied to the electrical energy storage system 16 at anytime from T1 and until any time after T3.

At block 60, the method may include controlling supply of electricalpower output from the electrical energy storage system 16 to the one ormore motors 44 of the propulsion system 18. For example, at or aftertime T3 as illustrated in FIG. 3, or at or after time T2 as illustratedin FIG. 4, the controller 22 may control the electrical energy storagesystem 16 to supply electrical energy to the one or more motors 44.Consequently, the electrical energy storage system 16 may supplement theelectrical energy being provided to the propulsion system 18 and maythus provide additional thrust.

The system 10, the apparatus 12 and the methods described above mayprovide several advantages.

First, the methods may provide a relatively fast transient thrustresponse by increasing the electrical power output from the powergeneration system 14 before it is needed by the propulsion system 18.For example, the one or more gas turbine engines 38 may take ten secondsto increase turbine shaft speed from three thousand revolutions perminute (corresponding to electrical power output P3) to ten thousandrevolutions per minute (corresponding to the first electrical poweroutput P1), whereas the one or more gas turbine engines may take threeseconds to increase turbine shaft speed from seven thousand revolutionsper minute (corresponding to the second electrical power output P2) toten thousand revolutions per minute (corresponding to the firstelectrical power output P1).

Second, as mentioned above, the methods may enable the power generationsystem 14 to decelerate relatively slowly and for excess energy to bestored in the electrical energy storage system 16 for later use. Wherethe power generation system 14 includes the one or more gas turbineengines 38, this may help to prevent the one or more gas turbine engines38 exceeding their compressor surge margin during deceleration and thusmay prevent damage to the one or more gas turbine engines 38.

Aircraft propulsion specifications usually include requirements for howquickly thrust can be reduced to idling level in the event of a rejectedtake-off, and so on. The methods and apparatus 12 may be configured tomeet such a thrust reduction time target whilst allowing the powergeneration system to decelerate more slowly and diverting the excessgenerated electrical power from the propulsion system 18 to theelectrical energy storage system 16. The methods and apparatus 12 mayallow the power generation system 14 to be designed for slower powertransients, and for example, to be operated without the need forhandling bleed valves.

Third, the electrical power output from the power generation system 14is diverted to the electrical energy storage system 16 between times T1and T3 (as illustrated in FIG. 3) or between times T1 and T2 (asillustrated in FIG. 4) to charge the electrical energy storage system16. The stored electrical energy may be supplied to the propulsionsystem 18 at a later time to provide thrust. For example, the storedelectrical energy may be supplied to the propulsion system 18 inaddition to the electrical energy supplied by the power generationsystem 14 to provide additional thrust between times T3 and T4 (asillustrated in FIG. 3) or between times T2 and T3 (as illustrated inFIG. 4). By way of another example, the propulsion system 18 may solelyreceive the stored electrical energy in geographical areas (such astaxiways at an airport) where emissions from the power generation system14 are undesirable, restricted or prohibited.

Fourth, the methods may enable the one or more gas turbine engines 38 tooperate with reduced (or zero) handling bleed flows. This mayadvantageously reduce the noise emissions from the one or more gasturbine engines 38.

Fifth, the methods may enable the electrical energy storage system 16 tobe relatively small since the electrical power output from the powergeneration system 14 is increased before it is needed by the propulsionsystem 18 and consequently, less (or zero) electrical energy may berequired from the electrical energy storage system 16 during thetransient manoeuvre.

It will be understood that the invention is not limited to theembodiments above-described and various modifications and improvementscan be made without departing from the concepts described herein. Forexample, the different embodiments may take the form of an entirelyhardware embodiment, an entirely software embodiment, or an embodimentcontaining both hardware and software elements.

Except where mutually exclusive, any of the features may be employedseparately or in combination with any other features and the disclosureextends to and includes all combinations and sub-combinations of one ormore features described herein.

We claim:
 1. Apparatus for controlling a power generation system, theapparatus comprising a controller configured to: identify a triggerindicative of a future change in electrical power output by the powergeneration system to a first power level; control the power generationsystem to change electrical power output to a second power level inresponse to the trigger, the second power level being equal to, ordifferent to, the first power level; and control supply of at least aportion of the electrical power output from the power generation systemat the second power level to an electrical energy storage system tocharge the electrical energy storage system.
 2. The apparatus as claimedin claim 1, wherein the trigger is indicative of a future increase inelectrical power output by the power generation system, and the secondpower level is equal to, or less than, the first power level.
 3. Theapparatus as claimed in claim 1, wherein the trigger is indicative of afuture decrease in electrical power output by the power generationsystem, and the second power level is equal to, or greater than thefirst power level.
 4. The apparatus as claimed in claim 1, wherein thecontroller is configured to: control the power generation system tochange electrical power output to the first power level from the secondpower level.
 5. The apparatus as claimed in claim 1, wherein thecontroller is configured to: control supply of electrical power outputfrom the power generation system to one or more motors of a propulsionsystem.
 6. The apparatus as claimed in claim 1, wherein the controlleris configured to: control supply of electrical power output from theelectrical energy storage system to one or more motors of a propulsionsystem.
 7. The apparatus as claimed in claim 1, wherein the controlleris configured to: receive a trigger signal from a user input device; andwherein the controller is configured to identify the trigger using thereceived trigger signal.
 8. The apparatus as claimed in claim 1, whereinthe controller is configured to: receive location data from a globalpositioning sensor; and wherein the controller is configured to identifythe trigger using the location data from the global positioning sensor.9. The apparatus as claimed in claim 1, wherein a vehicle comprises thepower generation system, and wherein the controller is configured toidentify the trigger using an operating mode of a component of thevehicle.
 10. The apparatus as claimed in claim 1, wherein the powergeneration system comprises a gas turbine engine.
 11. The apparatus asclaimed in claim 1, wherein the electrical energy storage systemincludes one or more batteries and/or one or more supercapacitors.
 12. Amethod of controlling a power generation system, the method comprising:identifying a trigger indicative of a future change in electrical poweroutput by the power generation system to a first power level;controlling the power generation system to change electrical poweroutput to a second power level in response to the trigger, the secondpower level being equal to, or different to the first power level; andcontrolling supply of at least a portion of the electrical power outputfrom the power generation system at the second power level to anelectrical energy storage system to charge the electrical energy storagesystem.
 13. The method as claimed in claim 12, wherein the trigger isindicative of a future increase in electrical power output by the powergeneration system, and the second power level is equal to, or less than,the first power level, or wherein the trigger is indicative of a futuredecrease in electrical power output by the power generation system, andthe second power level is equal to, or greater than the first powerlevel.
 14. The method as claimed in claim 12, further comprisingcontrolling the power generation system to change electrical poweroutput to the first power level from the second power level.
 15. Themethod as claimed in claim 12, further comprising controlling supply ofelectrical power output from the power generation system to one or moremotors of a propulsion system.
 16. The method as claimed in claim 12,further comprising controlling supply of electrical power output fromthe electrical energy storage system to one or more motors of apropulsion system.
 17. The method as claimed in claim 12, furthercomprising receiving a trigger signal from a user input device; andwherein the trigger is identified using the received trigger signal. 18.The method as claimed in claim 12, further comprising receiving locationdata from a global positioning sensor; and wherein the trigger isidentified using the location data from the global positioning sensor.19. The method as claimed in claim 12, wherein a vehicle comprises thepower generation system, and wherein the trigger is identified using anoperating mode of a component of the vehicle.
 20. A non-transitorycomputer readable storage medium comprising computer readableinstructions that, when read by a computer, cause performance of themethod as claimed in claim 12.